Lee and Clem has a one hundred percent chance of surviving seeing as they are central to the story, unless one of them gets bitten at some point in Episode 4 bringing emphasis to the title of the fifth Episode
Kenny may survive the episode depending on how compelled he is to find a boat in Savannah and when all the chips are down and when all hopes are lost, Kenny might be consumed by his sadness and may actually off himself, especially if he is drinking which tends to intensify feelings such as sadness.
Omid has a very small chance of survival based on the state of his leg, but seeing as it has been patched up somewhat in the latest trailer it may actually heal overnight just as Lee's leg did in Episode 1
Christa has a high chance of survival based on her and Omid's survival skills, but the chances might waver should Omid die (there is the chance that Christa may commit suicide as a result of Omid's death as hinted at a piece of artwork from the trailer of the game or she may die trying to save Omid when he is unable to run from the walkers).
Charles has the best chance of survival as he is the most stable out of the other characters (no detrimental events have transpired for him) and he has managed to survive on his own.
Ben's survival is debatable and his shame for indirectly killing almost everyone from the original group might either push him to tell the whole group about it (which might result in Kenny beating him to death or just beating on him and you have to get Kenny off him), Lee might kill him because he has done nothing useful since they have arrived in Savannah or he may just "punch his own ticket"
Walkie Talkie Man might survive and I think he may be an enemy in Episode 5, especially since one of the chapters in the episode is dubbed the Marsh House
I have no knowledge as to whether or not she will survive as she might be an important character or she may just be like the rest of the bandits (hell she could even be the guy who won the pre order contest and may be devoured by walkers at some point)